The effect of post-emission filtration systems on urban air quality

Ines Bamberger1, Johann Schneider2, Christoph K. Thomas2, Anke C. Nölscher1
1 Atmospheric Chemistry
2 Micrometeorology

P 4.1 in Poster Session

Dense city planning in combination with static atmospheric conditions and high traffic may lead to an accumulation of pollutants like nitrogen dioxide (NO2) in the surrounding air. Increased levels of air-pollution influence human health and reduce the livability in cities. Therefore, atmospheric NO2 concentrations are regulated by law. Despite decreasing tendency, the NO2 concentrations at urban hot-spots like the Landshuter Allee in Munich still exceed legal thresholds. Post-emission filtration systems may offer a short-term solution to this problem and and improve the air quality. However, studies which support the positive effect of such systems in the air volume of a street canyon are sparse.   

The goal of this study is to evaluate if and under which circumstances post-emission filtration systems may help to efficiently clean the air from nitrogen dioxide in direct vicinity to highly frequented roadways. Therefore, we installed nine post-emission filtration systems along the Landshuter Allee and tested their efficiency in the field by selectively regulating the air flow through the systems, while continuously measuring the NO2 concentrations as well as meteorological conditions including turbulent transport. Performing measurements in the wind cone exiting the post-emission filtration systems while regularly switching between power off and power on, we successfully separated the air filtration effect from the traffic- and mixing-driven variability in NO2 concentrations and quantified a decrease of up to 18 % in NO2 concentrations when the air filtration systems were powered on compared to them being powered off.

This project is funded by the Bavarian Ministry of the Environment and Consumer Protection.

Keywords: urban air quality, air filtration systems, nitrogen dioxide, air pollution, air purification
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